flexible template assignment

[mkolar]

Problem.
Currently we only differentiate between render and publish templates for publish, however introduction of multi-roots, brings the possibility to expand this radically. If a studio wants to store alembic cashes on a separate storage we can allow it with multi-roots, but we'd still need change the actual plugin that handles the cache extraction and inject anatomy_template to instance.data["representation"].

Possible solution
We should make sure that every place where we assign a particular template to an output, should be easily configurable from presets. This should be simple enough by making template_name a class attribute, which are automatically overridden by values from presets.

[iLLiCiTiT]

Add to IntegrateNew presets which define what anatomy template key will be used for which family representation.

[create-issue-branch]

Branch feature/93-flexible_template_assignment created!